1. Field of the Invention
The present invention relates to a locating device, particularly for locating trapped victims under avalanches, under debris or under collapsed buildings, including a receiving unit for signals from transmitters, preferably a transmitter connected to three preferably orthogonally arranged ferrite rod antennas, optical and/or acoustic display units, as well as a method for the operation of a locating device, particularly for locating trapped victims under avalanches, under debris or under collapsed buildings, whereby incoming signals of one or several transmitters are monitored by a receiving unit.
2. The Prior Art
Current portable devices for locating trapped victims are equipped with devices to detect and display the magnitude and possibly the direction of the magnetic field strength of a transmitter. This displayed information is used to advance toward the trapped victim along field lines. In most cases, one or two ferrite receiving antennas are provided for this purpose which are mounted in a common housing together with the processing electronics and the display devices whereby the possible rod length limits the range of transmission and whereby accurate point locating is also made difficult in the case of two antennas. The rescuer may reach positions during the search for a point location at which the field strength is oriented completely vertical and at which the horizontal plane equals zero. Inexperienced rescuers cannot determine the exact location of the trapped victim in this case. In such cases, even devices with a “virtual” antenna are useless as described, for example, in EP 0 855 600 A2. Otherwise, devices having three identical, preferably orthogonally oriented actual antennas, as disclosed in EP 0 733 916 A2, for example, are too bulky and unmanageable or they have too short of a range for a meaningful search while being designed of small dimensions.
The object of the present invention was therefore to provide a device of the aforementioned type which makes possible, in a simple manner, locating of a trapped victim at a range as large as possible without being susceptible to operational errors and which is nevertheless dimensioned in such a compact manner that is does not restrict the movement of the operator during the search, and whereby it can be carried along during other activities. An additional object of the invention was a method to operate a device of the aforementioned type with which locating of several trapped victims is possible in succession in a simple and reliable manner.